https://github.com/jackychiu/slb

Simple Load Balancer
https://github.com/jackychiu/slb

concurrency golang load-balancer pool

Last synced: about 9 hours ago
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Simple Load Balancer

• Host: GitHub
• URL: https://github.com/jackychiu/slb
• Owner: JackyChiu
• License: mit
• Created: 2017-10-28T02:22:25.000Z (about 7 years ago)
• Default Branch: master
• Last Pushed: 2018-02-28T03:59:38.000Z (over 6 years ago)
• Last Synced: 2024-06-21T11:09:54.074Z (5 months ago)
• Topics: concurrency, golang, load-balancer, pool
• Language: Go
• Homepage:
• Size: 13.9 MB
• Stars: 135
• Watchers: 3
• Forks: 9
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Simple Load Balancer [![CircleCI](https://circleci.com/gh/JackyChiu/slb.svg?style=svg)](https://circleci.com/gh/JackyChiu/slb) [![Go Report Card](https://goreportcard.com/badge/github.com/JackyChiu/slb)](https://goreportcard.com/report/github.com/JackyChiu/slb)

slb is a simple single node HTTP load balancer

Available strategies are: 

- [Round Robin](round_robin.go)

- [Least Busy](least_busy.go)

These strategies for the node pools are also concurrent safe.

## Demo

### Round Robin

```bash

bin/slb -strategy round_robin -config config.json

```

![](.github/round_robin.gif)

### Least Busy

```bash

bin/slb -strategy least_busy -config config.json

```

![](.github/least_busy.gif)

The pool was tested by a requester that produces tasks at a random interval, faster than the time it takes to complete the requests itself. 

The tasks also take an inconsistent amount of time to finish.

In this example the requests were just sleeps.

The standard deviation measures how spread out the pending requests are across workers, giving us an idea of how well the pool is distributing work.

As time goes by the average load goes up the standard deviation remains about the same!

**Basically the smaller the `Std Dev` the better work is being distributed!**

It's worth noting that because the requests aren't equal in the amount of work, the round robin balancer's standard deviation starts to climb.

While the least busy strategy keeps the amount of pending tasks in account and results in a better distribution of requests. 

## Try The Demo

```bash

# clone the project

go get github.com/JackyChiu/slb

cd $GOPATH/src/github.com/JackyChiu/slb

# make project

make all

# start local servers (only for demo)

bin/servers -config config.json

# start balancer server

bin/slb -strategy  -config config.json

# start the requester (only for demo)

bin/requester

```

A json file is used to specify hosts that are in the node pool, and the port that the load balancer to run on.

```json

{

  "port": 8000,

  "hosts": [

    "cool-app01.mydomain.com",

    "cool-app02.mydomain.com",

    "cool-app03.mydomain.com",

    "cool-app04.mydomain.com"

  ]

}

```